System Bits: Aug. 18

Optical computing for big data
Given the potential for optical electronics to be applied to big data processing tasks, alumni of the University of Cambridge, including from the Department of Engineering, have gone on to found Optalysys, a company with the goal of making computer processors that use light instead of electricity.

The Cambridge spinout’s latest achievement is a functioning prototype of a scaleable, lens-less optical processor able to perform mathematical calculations. The design, codenamed Project GALILEO, represents a breakthrough in scaleable, practical optical processing that calculates at the speed of light and in parallel. Applications for this research are in weather forecasting, vehicle aerodynamics and big data analysis for genomics and financial analysis.

Two other projects are on the horizon: One is in gene sequencing and analysis with the establishment of the Genome Analysis Centre; other activities include a project with a major Formula 1 team as well as possible application in financial institutions.
The company’s technology is based on research that Nicholas New performed whilst earning his PhD at Cambridge in Optical Pattern Recognition.

High temp metal alloy for sensors
ETH Zurich researchers have produced a thin film and extremely fine pillars from a new class of alloys made of multiple finely distributed elements, resistant to extreme pressures and temperatures. The researchers believe the material will be of interest in high-pressure and high-temperature applications, such as sensors that are required to operate in extreme conditions.

Good deformability: a pillar with a diameter of one micrometer before (left) and after (right) high-pressure mechanical deformation. (Source: ETH Zurich)

Humans have been making metal alloys for thousands of years in order to obtain materials with desirable properties. Traditionally, these alloys consisted of a main metal with smaller quantities of one or a few other elements combined during a smelting process. In high-entropy alloys, however, the composition is different. This new class of alloys has been high on the agenda for materials scientists for the past few years, as it offers high strength combined with temperature- and corrosion-resistance. High-entropy alloys typically consist of four or five metallic elements.

The ETH researchers used a high-entropy alloy to create a film just 3 micrometres thick, into which they milled a structure consisting of pillars with a diameter ranging from 100 nanometres to 1 micrometre. The alloy contains equal proportions of the elements niobium, molybdenum, tantalum and tungsten.

As they found, these “micropillars” made of the high-entropy alloy have very special properties: they are 10-times stronger than a block made of the same material. Furthermore, the pillars can be compressed by up to around a third of their length under high pressures without become brittle or cracking – scientists refer to this deformability as ductility. And, in the end, the material also exhibits enormous temperature-resistance: it survived three days at 1,100 degrees Celsius with no significant change to its external or internal structure – in stark contrast to pure tungsten, which the scientists also subjected to heat treatment as a control. Following heat treatment, micropillars made of the high-entropy alloy perform significantly better in terms of strength and ductility than those made of pure tungsten. This is despite the fact that the high-entropy alloy’s melting point is significantly lower than that of pure tungsten (around 2,900 versus 3,400 degrees Celsius).

Microfluidics device models cancer
Replicating how cancer and other cells interact in the body is somewhat difficult in the lab, and biologists generally culture one cell type in plastic plates, which doesn’t represent the dynamic cell interactions within living organisms. But now, MIT spinout AIM Biotech has developed a microfluidics device that lets researchers co-culture multiple cell types in a 3D hydrogel environment that mimics natural tissue.

The device can help researchers better study biological processes, such as cancer metastasis, and more accurately capture how cancer cells react to chemotherapy agents, according to AIM Biotech co-founder Roger Kamm, the Cecil H. Green Distinguished Professor in MIT’s departments of mechanical engineering and biological engineering.

Designed originally for Kamm’s lab, the new commercial device is a plastic chip with three chambers: a middle chamber for hydrogel and any cell type, such as cancer cells or endothelial cells (which line blood vessels), and two side channels for culturing additional cell types. The hydrogel chamber has openings along each side, so cells can interact with each other, as they would in the body. Cancer drugs or other therapeutics can then be added to better monitor how cells respond in a patient.

AIM Biotech’s microfluidics device (shown here) has an array of culturing sections, each with three chambers: a middle chamber for hydrogel and any cell type, and two side channels for culturing additional cell types. (Source: MIT)